This invention relates to a pointing device for use in moving a cursor displayed on a display and, in particular, to a signal processing circuit for the pointing device.
As one of the pointing devices of the type described, a mouse device has been used in an information processing apparatus for processing video information or a video game machine. The mouse device generally includes a rotary encoder having a rotary ball. In order to move a cursor displayed on a display, the mouse device is moved on a plane such as a desk to thereby rotate the rotary ball. The number of revolution of the rotary ball is detected by the rotary encoder. With reference to the number of revolution thus detected, a position of the cursor on an X-Y coordinate plane is determined. Briefly, the number of revolution is substantially converted into the position on the X-Y coordinate plane to correspondingly move the cursor displayed on the display.
As described above, the mouse device has a rotary element such as the rotary encoder combined with the rotary ball. Due to presence of such a rotary mechanism, the mouse device inevitably has a complicated structure and can not be formed into a thin shape.